Cerebral edema after traumatic brain injury and severe stroke is a life-threatening condition that is refractory to conventional treatments in a significant population of patients. Current treatments (i.e. hyperventilation, osmotic diuretic(s) or hypothermia) are associated with serious side effects that increase with prolonged use. Intracranial hypertension is caused by elevated tissue water content, primarily due to hyperosmosis of ischemic tissue. Thus, removal of water may be an effective treatment. The research plan details feasibility tests of a novel, safe, and effective method of removing water that can be placed within a standard ventriculostomy catheter. Pilot studies have shown a 50% reduction in water uptake by brain tissue in an ex vivo model. In vitro studies will be completed to optimize catheter material and design. Further ex vivo tissue studies will be completed, as well as studies of human post-traumatic CSF. Tissue water removal in a scale model of the human cerebroventricular system will be tested. The goal is to reduce edema in tissue samples without an increase in CSF osmolarity. Successful development and marketing of this proprietary methodology could significantly reduce morbidity and mortality after human TBI, stroke, and other neurological disorders associated with cerebral edema. In Phase II, further efficacy testing of catheter systems is planned in experimental models of cerebral edema and human studies. [unreadable] [unreadable]